In the other end member, SrIrO\(_3\)  (SIO), strong SOC leads to a splitting of the Ir-\(t_{2g}\)  orbitals into completely filled \(j_{\rm eff}=3/2\)  band and half-filled \(j_{\rm eff}=1/2\) . While SIO exhibits a quenched spin and orbital magnetic moment and topological crystalline semimetalic character [1]}, [2]}, [3]}, [4]}, [5]} in space group \(Pbnm\)  [6]}, in other iridates such as the Ruddlesden-Popper (RP) Sr\(_2\) IrO\(_4\)  with Ir\(^{4+}\)  (5d\(^5\) ) the interplay of electronic correlations and SOC opens a gap giving rise to a \(j_{\rm eff}=1/2\)  Mott insulator [7]}, [8]}, [9]}, [10]}, [5]}, [12]}, [13]}.
